Pharmaceutical compositions for headache, migraine, nausea and emesis

ABSTRACT

S-alkylsiothiouronium derivatives such as S-ethylisothiouronium diethylphosphate are used for the treatment of headaches, in particular, migraines, as well as for the prevention or treatment of nausea and vomiting. The compositions of the invention are also effective in preventing or alleviating emesis associated with migraines or other medical conditions such as chemotherapy or radiotherapy, as well as other symptoms of migraines including phonophobia and photophobia.

This application is a continuation of the US national stage designationof International Application PCT/IL01/00817 filed Aug. 30, 2001, thecontent of which is expressly incorporated herein by reference thereto,and which claims the benefit of U.S. provisional application 60/229,812filed Sep. 5, 2000.

FIELD OF THE INVENTION

The present invention relates to the use of S-alkylisothiouroniumderivatives, including, but not limited to, S-ethylisothiouroniumdiethylphosphate, for the prevention or treatment of headache, includingbut not limited to migraine, and for the prevention or treatment ofemesis, and more particularly, to the alleviation of migraine symptoms,including but not limited to headache, nausea and vomiting.

BACKGROUND OF THE INVENTION

Headache is a term used to describe a varied set of symptoms, ranging inintensity from mild discomfort to the very severe syndrome known by thename of migraine.

While the most severe and debilitating form of headache is migraineheadache there are several other types of headaches that warrantconsideration in terms of prevalence, including but not limited topremenstrual syndrome (PMS) associated headaches and the conditionassociated with morning after alcohol consumption, commonly referred toas hangover. Symptoms such as headache, fever, chills, nausea, muscleand nerve pain, lethargy, and others are often manifested during thesyndrome known as hangover.

While not life-threatening conditions, both PMS and hangover can be veryunpleasant, as well as detrimental on the job or at home. Currently, themost common methods of treating these conditions includeself-administration of NSAIDs, painkillers, and other prescription andOTC drugs.

The following publications provide some background art relating toheadaches in general and migraines in particular, their causes and theirmodes of treatment:

1. Capobianco “An overview of the diagnosis and pharmacologic treatmentof migraine” Mayo Clin. Proc. (1996) 71:1055–1066.

2. Cohen “Migraine Headache and the Managed Care Formulary” DrugsBenefit Trends (1996) 8(8) 28–30, 33–34,41.

3. Diamond, “Do Non-Steroidal Anti-Inflammatory Agents Have a Role inthe Treatment of Migraine Headaches” Drugs (1989) 37:755–760.

4. Klapper, “Toward a standard drug formulary for the treatment ofheadache” Headache (1995) April, 225–227.

5. Kumar, “Recent advances in the acute management of migraine andcluster headaches” Journal of General Internal Medicine (1994)9:339–348.

6. Matthew, “Serotonin 1D (5-HT1D) agonists and other agents in acutemigraine” Advances in Headache, (1997) 15(1): 61–81.

7. Pradalier, “Treatment Review: Non-Steroid Anti-Inflammatory Drugs inthe Treatment and Long-Term Prevention of Migraine Attacks” Headache(1988) 28:550–557.

8. Pryse-Phillips, “Guidelines for the diagnosis and management ofmigraine in clinical practice” Can. Med. Assoc. J. (1997)156(9):1273–1287.

9. Wilkinson, “Migraine and cluster headache—their management withsumatriptan: a critical review of the current clinical experience”Cephalalgia (1995) 15:337–357.

The following paragraphs highlight the present knowledge regardingmigraines and their treatment.

Migraine Symptoms and Diagnosis

Migraine is a severe episodic headache characterized by unilateral,intense pulsating headache, nausea, vomiting, sparkling, rainbow-likecolors, blank spots in the field of vision, or other auras andsensitivity to light and sounds [Larson, E. David, M.D. Editor-in-Chief.“Mayo Clinic Family Health Book” 1994. pp. 502–503]. Migraine refers toa group of symptoms that may occur together. The most noted one is anincapacitating headache, on one side or over the entire head, which canlast from 2 to 72 hours. The pain is usually described as throbbing.These headaches are usually, but not always, associated with feelingsick in the stomach or being sensitive to light, sound or movement ofthe body. The pain is quite severe and often the person with migrainemust stay in bed. Dietary, emotional, hormonal and environmental factorsmay trigger an attack.

In practice there are two types of migraine. The most common is calledmigraine without aura (Common Migraine) and this accounts for 85% of allsufferers. The second most common type is called migraine with aura(Classical Migraine), which accounts for most of the remaining 15% ofsufferers. Aura is a disturbance in the nervous system, which oftenprecedes the headache.

Migraine sufferers sometimes get a warning signal before an attack. Someexperience “aura,” a disruption of brain function that occurs twenty tothirty minutes before the attack. This is characterized by visualdisturbances like flashing lights and blurred vision or a sensation inthe body of pins and needles affecting one limb or one side. Thesedisturbances are usually short-lived and almost invariably pass awayleaving no long-lasting effects. Other migraine sufferers experience a“prodrome”, which occurs several hours or even a day before an attack isinitiated. The symptoms may include yawning, fatigue, mood changes, foodcravings, and sensitivity to light (photophobia), sound (phonophobia),touch and/or odors. In most of those who have a prodrome, the patternand headache location remains the same with each migraine attack. Othercommon symptoms include numbness or a tingling feeling around the lipsor hands, hallucinations, loss of speech, symptoms of depression,irritability (some people seek seclusion in a dark room), restlessness,nausea, or loss of appetite, which occur in about 20% of the migrainesufferers. Similar percentages of migraine sufferers lose vision in aspecific area (called a blind spot or scotoma) or see jagged,shimmering, or flashing lights. Less commonly, images are distorted; forinstance, objects appear smaller or larger than they are.

Migraine is a chronic disorder without cure. No laboratory test isavailable to help diagnose migraines, but usually the headaches'distinct pattern makes them easy to identify. The headaches are notlife-threatening, and there is no proof that they lead to otherdisorders [Larson, E. David M.D. Editor-in-Chief. “Mayo Clinic FamilyHealth Book” 1994. p. 503]. The public health significance of migraineis often overlooked, probably because of its episodic nature and thelack of mortality attributed to disorder. Migraine is, however, oftenincapacitating, with considerable impact on social activities and work.

Prevalence

The prevalence of migraine is relatively high and said to beapproximately 6% of the male population and 18% of the femalepopulation. The female preponderance of migraine appears after puberty;in many patients, migraine occurs at the time of menses and improvesduring pregnancy. It is estimated that only in the US, about 35 millionpeople suffer from migraine. Episodes of migraines can occur weekly insome people; others may have less than one a year [Griffith, H. Winter,M.D. “All-New Third Edition Complete Guide to Symptoms, Illness &Surgery” July 1995. p. 425].

Current treatment of migraine

There are several recognized migraine therapeutic drugs. Treatment formany patients having the occasional migraine usually involves simpleanalgesics (usually in combination with an antiemetic, but suchtreatments are of limited value), non-steroidal anti-inflammatoryagents, or specific agents such as ergotamines or triptans. While nomore than sporadically effective, the conventional art recognized thatanti-migraine drugs are thought to initially relieve migrainepredominantly by causing vasoconstriction. Unfortunately, thisconventional art recognized that migraine drugs are associated withsignificant negative side effects that are linked to excessivevasoactivity in regions of the body not involved in the pathogenesis ofmigraine. This remote vasoactivity is an effect without any therapeuticbenefit to the treatment of migraine. These vasoactive drugs are, infact, contraindicated in patients with coexisting cardiovasculardiseases, or the risk of cardiovascular diseases, such as hypertension,coronary artery disease, or peripheral vascular diseases. Other reportedsignificant side effects are chest pain or pressure, flushing,generalized tingling sensations, nausea, vomiting, pain in the legs andarms, asthenia, drowsiness, and dizziness. Preventative agents such asbeta-blockers, tricyclic antidepressants and sodium valproate can reducebut not eliminate migraine attacks in some patients. In the remainingpopulation of migraine sufferers, and in those with intolerable sideeffects from available drugs, there is a lack of conventionalpharmaceutical preparations that exhibit therapeutic effect, withoutsevere side effects. Thus, there remains a great need for migrainespecific medications.

OTC analgesics: In some forms of migraine, certain patients have foundtotal or partial relief with the use of non-prescription analgesics suchas acetaminophen, aspirin, ibuprofen, and other non-steroidalanti-inflammatory agents, including naproxen and naproxen sodium.However, these agents, when taken alone, are rarely effective inproviding complete and rapid alleviation of all the symptoms ofmigraine, especially when the symptoms of the attack already includenausea or vomiting. Moreover, their onset of action is slow such thatrelief sometimes does not occur for at least several hours.

Ergotamine Drugs: One of the common treatments for migraine is theadministration of compounds having vasoconstrictor properties such asergotamines or ergotamine-like agents. However, ergotamine is anon-selective vasoconstrictor, which constricts blood vessels throughoutthe body and has undesirable and potentially dangerous side effects.Ergotamines should not be used by patients with peripheral vasculardisease, coronary heart disease, hypertension, impaired hepatic or renalfunction, severe pruritis or sepsis. It is also contraindicated in womenwho are, or may become, pregnant. Nausea and vomiting have been reportedin up to 10% of patients receiving therapeutic doses of ergotamine.Acute ergotism is a particularly pernicious side effect of ergot drugs,and is characterized by severe central and peripheral vasoconstriction,sometimes resulting in amputation of the affected limbs and/or digits,nausea, vomiting, diarrhea, colic, headache, vertigo, paresthesia, andpossibly convulsive seizures. Chronic ergotism is characterized byintermittent claudication, muscle pains, numbness, and cold extremitiesas well as other gastrointestinal and central nervous system (CNS) sideeffects. There are treatments, which involve the administration of highdosage of caffeine with ergots or other pharmacological agents.Moreover, ergots and caffeine are potentially addictive with welldocument withdrawal symptoms.

Triptan drugs (serotonin agonists): Another treatment is theadministration of newer therapeutic agents known as serotonin agonistsor 5-hydroxy tryptamine (5-HT) agonists. The first of this family,sumatriptan, was undoubtedly, a significant advance in migraine therapy.Sumatriptan succinate sold under the trademark IMITREX by Glaxo WellcomeInc. Despite sumatriptan utility in migraine treatment it has certainlimitations; for example low oral bioavailability, high headacherecurrence and contraindication in patients with coronary arterydisease.

The main mechanism of action of triptans in migraine is to constrictdilated cranial extracerebral blood vessels. In addition, the triptanscan reduce neuropeptide release and plasma protein extravasation acrossdural vessels and inhibit impulse transmission centrally withintrigeminovascular system.

In general, management of migraine is complicated by the lack of asingle therapy, which is effective in all patients with the samemigraine type and by the need to select either an abortive orprophylactic method of treatment for these migraines. Furthercomplications involve the current use of drugs that cause dependencewith extended use, such as the ergot alkaloid ergotamine. Anotherimportant consideration is that the more effective anti migraine agentsin current use, e.g., the ergots, methysergide, produce severeuse-limiting side effects with long term usage.

There is thus a need for an effective drug for alleviating or treatingmigraine symptoms, which can be used either, before the attack, e.g., atthe aura phase, or during the attack, so as to rapidly alleviatesymptoms of migraine during a migraine attack and which is devoid ofside effects.

Anti-Emetic Drugs

A particularly important application for anti-emetic agents is in theprevention and treatment of nausea and vomiting associated with cancerchemotherapy. Emesis is a well-known and frequent side-effect of cancerchemotherapeutic agents, such as cisplatin. It causes serious problemsin cancer chemotherapy, and in some patients emesis is so severe thattherapy must be discontinued. Anti-emetic agents are therefore oftenadministered in order to alleviate this side-effect of the cancerchemotherapeutic agent. The anti-emetic agents employed are usuallybenzamide derivatives, such as metoclopramide, which have dopamineantagonist activity. In view of their dopamine antagonist activitybenzamide derivatives such as metoclopramide themselves exhibit seriousand undesirable side-effects, such as extra-pyramidal effects, i.e.tardive dyskinesia, acute distonia, akathisia and tremor.Physiologically acceptable salts of the carbazolones are described inthe U.S. Pat. No. 5,578,628 as potent anti-emetics, which are selectiveantagonists of 5-hydroxytryptamine (5-HT) at neuronal 5-HT receptors ofthe type located on terminals of primary afferent nerves, and which arealso believed to be present in the central nervous system.

There is thus a need for a safe and effective anti-emetic agent andgastric mobility stimulant, while devoid of undesirable side effects ofknown anti-emetics which elicit their action via various CNS receptors.

U.S. Pat. No. 6,160,008 discloses the use of S-alkylisothiouroniumderivatives, including several novel compounds, as medicaments forincreasing arterial blood pressure or for protecting subjects againsthyperoxia. These compounds are suggested for the treatment of acutehypotension, e.g., shock conditions and chronic arterial hypotension oroxygen poisoning. The invention is exemplified by the hypertensiveeffect of S-ethylisothiouronium diethylphosphate under variousconditions. However, U.S. Pat. No. 6,160,008 neither teaches norsuggests the use of S-alkylisothiouronium derivatives for treatingheadache, migraine, or nausea and vomiting.

SUMMARY OF THE INVENTION

Unexpectedly it is now disclosed that S-alkylisothiouronium saltderivatives that were known as hypertensive agents, are also highlyefficient in alleviating headache in general and symptoms of migraine,in particular. While reducing the present invention to practice it wasalso found that these S-alkylisothiouronium salt derivatives wereeffective in treating nausea and emesis. Subjects with migraine weresuccessfully treated with unexpectedly lower doses ofS-ethylisothiouronium diethylphosphate, than required foranti-hypotensive applications. Treatment initiated at the peak of themigraine attack, consistently showed relief within 60 minutes followingthe drug administration. In some cases dramatic improvement was reportedwithin about 15 minutes.

Thus, according to one aspect of the present invention there is provideda pharmaceutical composition for treatment of headache, migraine, nauseaor emesis comprising, as an active ingredient, a compound having thegeneral formula I:

wherein,

-   -   R₁ is a linear or branched, saturated or unsaturated alkylene,        comprising one to eight carbon atoms, optionally substituted        with one or more substituent selected from the group consisting        of halogen, primary, secondary or tertiary amine, primary,        secondary or tertiary alcohol, or interrupted by one or more        heteroatom selected from the group consisting of O, N, and S;    -   R₂, R₃, R₄ and R₅ are each independently a hydrogen, hydroxy,        linear or branched lower alkyl, linear or branched lower        alkenyl, linear or branched lower alkynyl, lower alkoxy,        alkoxyalkyl, cycloalkyl, cycloalkylalkyl, lower thioalkoxy,        nitro, amino, cyano, sulfonyl, haloalkyl, carboaryloxy,        carboalkylaryloxy, alkyl sulfoxide, aryl sulfoxide, alkyl        sulfone, aryl sulfone, alkyl sulfate, aryl sulfate, sulfonamide,        thioalkyl, optionally substituted by halogen;    -   A⁻ is a physiologically acceptable anion;    -   together with and a pharmaceutically acceptable carrier or        diluent.

According to currently preferred embodiments of the invention describedbelow, the physiologically acceptable anion is an anion derived from aphosphorus containing acid, more preferably the group consisting of ananion derived from a phosphorus acid ester, or amide, most preferablythe anion is derived from a mono or di-alkyl ester of a phosphorouscontaining acid.

According to yet another aspect of the present invention there isprovided a method of treating a subject suffering from headache,migraine, or nausea the method comprising the step of administeringpharmaceutical composition comprising a therapeutically effective amountof a compound having the general formula (I):

wherein,

-   -   R₁ is a linear or branched saturated or unsaturated alkylene,        comprising one to eight carbon atoms optionally substituted with        one or more substituent selected from the group consisting of        halogen, primary, secondary or tertiary amine, primary,        secondary or tertiary alcohol, or interrupted by one or more        heteroatom selected from the group consisting of O, N, and S;    -   R₂, R₃, R₄ and R₅ are each independently a hydrogen, hydroxy,        linear or branched lower alkyl, linear or branched lower        alkenyl, linear or branched lower alkynyl, lower alkoxy,        alkoxyalkyl, cycloalkyl, cycloalkylalkyl, lower thioalkoxy,        nitro, amino, cyano, sulfonyl, haloalkyl, carboaryloxy,        carboalkylaryloxy, alkyl sulfoxide, aryl sulfoxide, alkyl        sulfone, aryl sulfone, alkyl sulfate, aryl sulfate, sulfonamide,        thioalkyl, optionally substituted by halogen;    -   A⁻ is a physiologically acceptable anion.

According to another aspect of the present invention there is provided amethod of preparing a medicament, for headache, migraine or nausea, themethod comprising the step of mixing, as an active ingredient, acompound having the general formula (I):

wherein,

-   -   R₁ is a linear or branched saturated or unsaturated alkylene,        comprising one to eight carbon atoms optionally substituted with        one or more substituent selected from the group consisting of        halogen, primary, secondary or tertiary amine, primary,        secondary or tertiary alcohol, or interrupted by one or more        heteroatom selected from the group consisting of O, N, and S;    -   R₂, R₃, R₄ and R₅ are each independently a hydrogen, hydroxy,        linear or branched lower alkyl, linear or branched lower        alkenyl, linear or branched lower alkynyl, lower alkoxy,        alkoxyalkyl, cycloalkyl, cycloalkylalkyl, lower thioalkoxy,        nitro, amino, cyano, sulfonyl, haloalkyl, carboaryloxy,        carboalkylaryloxy, alkyl sulfoxide, aryl sulfoxide, alkyl        sulfone, aryl sulfone, alkyl sulfate, aryl sulfate, sulfonamide,        thioalkyl, optionally substituted by halogen;    -   A⁻ is a physiologically acceptable anion;    -   together with and a pharmaceutically acceptable carrier or        diluent.

According to further features in preferred embodiments of the invention,the physiologically acceptable anion is selected from the groupconsisting of an anion derived from a phosphorus containing acid, aphosphorous acid ester, a phosphorous acid amide, acetate, adipate,alginate, citrate, aspartate, benzoate, benzenesulfonate, bitartarate,bisulfate, butyrate, camphorate, camphorsulfonate, digluconate,glycerophosphate, hemisulfate, heptanoate, hexanoate, fumarate,2-hydroxyethanesulfonate, isothionate, lactate, maleate,methanesulfonate, nicotinate, 2-naphthalenesulfonate, oxalate, palmoate,pectinate, 3-phenylpropionate, pivalate, propionate, succinate,tartrate, thiocyanate, glutamate, bicarbonate, p-toluenesulfonate,chloride, bromide, iodide and undecanoate.

According to currently preferred embodiments of the invention describedbelow, the physiologically acceptable anion is an anion derived from aphosphorus containing acid, more preferably the group consisting of ananion derived from a phosphorous acid ester or amide, most preferablythe anion is derived from a mono or di-alkyl ester of a phosphorouscontaining acid.

According to still further features in the preferred describedembodiments, the medicament is packed and is identified as havinganti-headache, anti-migraine or anti-emetic activity.

According to still further features in the described preferredembodiments the compound is selected from the group consisting of:

-   -   S-methylisothiouronium methylphosphite;    -   S-methylisothiouronium dimethylphosphate;    -   S-ethylisothiouronium metaphosphate;    -   S-ethylisothiouronium ethylphosphite;    -   S-ethylisothiouronium diethylphosphate;    -   S-propylisothiouronium propylphosphite;    -   S-isopropylisothiouronium metaphosphate;    -   S-isopropylisothiouronium isopropylphosphite;    -   S-butylisothiouronium dibutylphosphate; and    -   S-isobutylisothiouronium isobutylphosphite.

According to still further features in the described preferredembodiments the anti-headache, anti-migraine, anti-nausea or anti-emeticmedicament is formulated for oral, or parenteral modes ofadministration. Among the parenteral routes of administrationparticularly preferred formulations are suitable for injection,sublingual, transdermal, transmucosal or inhalable administration.

According to still further features in the described preferredembodiments the anti-migraine medicament is formulated as tablets orcapsules.

According to still further features in the described preferredembodiments each of the tablets or capsules includes between 10 and 300mg of the compound.

According to still further features in the described preferredembodiments each of the tablets or capsules includes between 20 and 200mg of the compound.

According to still further features in the described preferredembodiments each of the tablets or capsules includes between 30 and 80mg of the compound.

According to still further features in the described preferredembodiments, the method further comprising the steps of packaging themedicament and identifying the medicament as having anti-headache,anti-migraine, anti-nausea or anti-emetic activity.

According to preferred embodiments the therapeutically effective amountranges between 0.1 and 3 mg/kg body weight.

According to further preferred embodiments the therapeutically effectiveamount ranges between 0.4 and 1.6 mg/kg body weight.

According to currently most preferred embodiments the therapeuticallyeffective amount ranges between 0.5 and 1.2 mg/kg body weight.

According to still further features in the described preferredembodiments the therapeutically effective amount is selected such thatin less than 60 minutes following administration a substantial relief inmigraine symptoms is experienced.

According to certain preferred embodiments the compound is administeredfollowing onset of symptoms of a headache, in particular a migraine, ornausea.

According to additional preferred embodiments the compound isadministered upon onset of a headache, particularly a migraine, ornausea.

It is understood that the while migraine is the most severe form ofheadache, the methods of treatment of the present invention are suitablealso for other types of headaches and nausea, including but not limitedto PMS or hangover associated headaches and nausea. This is particularlyappropriate due to the negligible side effects observed in humansubjects with the compositions and methods of the present invention.

Compounds of formula (I) inhibit emesis. The compounds are thereforealso of use as anti-emetic agents, i.e. in the prevention and treatmentof nausea and vomiting. The compounds are especially valuable for theprevention of emesis induced by cancer chemotherapeutic agents such ascisplatin. Particular mention may also be made of the treatment ofradiation-induced emesis. Thus, the compounds of formula (I) may be usedin the prevention of emesis induced by radiation therapy, e.g.irradiation of the thorax or abdomen, such as in the treatment ofcancer; or in the treatment of radiation sickness. It will beappreciated that the compounds of formula (I) may be usedprophylactically and references in this specification to treatmentinclude prophylactic treatment as well as the alleviation of acutesymptoms.

According to still further features in the described preferredembodiments the step of administering the compound is effected at orprior to onset of nausea. It will be appreciated by the skilled artisanthat oral administration may be less desirable after onset of nausea.

The present invention successfully addresses the shortcomings of thepresently known medications by providing an efficient compound fortreating and/or alleviating the symptoms of headache, in particularmigraine, or nausea. The currently preferred compound had no apparentside effects, was shown to be potent in low doses and to elicit atherapeutic/relieving effect within a short time period as compared tocurrently marketed drugs.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to the use S-alkylisothiouroniumderivatives for the treatment of headache, in particular migraine, ornausea and vomiting. The compositions of the invention are effective inpreventing or alleviating emesis associated with migraine or othermedical conditions such as chemotherapy or radiotherapy, as well asother symptoms of migraine including phonophobia and photophobia. Thesecompounds were known before to affect arterial blood pressure in casesof acute hypotension (e.g., following hemorrhage, trauma, shock orpoisoning).

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not limited in its applicationto the details set forth in the following description or exemplified inthe Examples section. The invention is capable of other embodiments orof being practiced or carried out in various ways. Also, it is to beunderstood that the phraseology and terminology employed herein is forthe purpose of description and should not be regarded as limiting.

As used herein, the term “migraine” is understood expansively to includea subset of headache characterized by unusual severity, unilateral,throbbing, headache pain persisting for 4–72 hours and can include alsoone or more of the following symptoms: nausea, vomiting, sensitivity tolight and/or sounds with or without a preceding “aura” and visualphotophobia (e.g., visual disturbances).

According to one aspect of the present invention there is provided ananti-headache, anti-migraine, anti-nausea or anti-emesis medicamentcomprising, as an active ingredient, a compound having the generalformula (I):

wherein,

-   -   R₁ is a linear or branched saturated or unsaturated alkylene,        comprising one to eight carbon atoms optionally substituted with        one or more substituent selected from the group consisting of        halogen, primary or secondary amine, primary or secondary        alcohol, or interrupted by one or more heteroatom selected from        the group consisting of O, N, and S;    -   R₂, R₃, R₄ and R₅ are each independently a hydrogen, hydroxy,        linear or branched lower alkyl, linear or branched lower        alkenyl, linear or branched lower alkynyl, lower alkoxy,        alkoxyalkyl, cycloalkyl, cycloalkylalkyl, lower thioalkoxy,        nitro, amino, cyano, sulfonyl, haloalkyl, carboaryloxy,        carboalkylaryloxy, alkyl sulfoxide, aryl sulfoxide, alkyl        sulfone, aryl sulfone, alkyl sulfate, aryl sulfate, sulfonamide,        thioalkyl, optionally substituted by halogen;    -   A⁻ is a physiologically acceptable anion;    -   together with and a pharmaceutically acceptable carrier or        diluent.

Preferably, the physiologically acceptable anion is derived, withoutlimitation, from a phosphorus containing acid, the group consisting ofan anion derived from a phosphorus containing acid, acetate, adipate,alginate, citrate, aspartate, benzoate, benzenesulfonate, bitartarate,bisulfate, butyrate, camphorate, camphorsulfonate, digluconate,glycerophosphate, hemisulfate, heptanoate, hexanoate, fumarate,hydrochloride, 2-hydroxyethanesulfonate, isothionate, lactate, maleate,methanesulfonate, nicotinate, 2-naphthalenesulfonate, oxalate, palmoate,pectinate, 3-phenylpropionate, pivalate, propionate, succinate,tartrate, thiocyanate, phosphate, glutamate, bicarbonate,p-toluenesulfonate, chloride, bromide, iodide and undecanoate.

According to currently preferred embodiments of the invention describedbelow, the physiologically acceptable anion is an anion derived from aphosphorus containing acid, more preferably the group consisting of ananion derived from a phosphorus acid ester or amide, most preferably theanion is derived from a mono or di-alkyl ester of a phosphorouscontaining acid.

As used herein and in the claims, the term “alkylene” refers to asaturated or unsaturated hydrocarbon chain including straight chain orbranched chain alkyl, alkenyl or alkynyl.

As used herein, the term “alkyl” refers to a saturated hydrocarbon chaincontaining 1 to 30, preferably 1 to 6 carbon atoms, such as, but notlimited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,tert-butyl, n-pentyl, n-hexyl, and the like. As used herein the termalkyl also reads on haloalkyls, which contain halogen atoms. Alkyl alsoincludes heteroalkyl with heteroatoms of sulfur, oxygen and nitrogen.

“Alkenyl” and “alkynyl” are used to mean straight or branched chainhydrocarbon groups having from 2 to 12 carbons and unsaturated by adouble or triple bond respectively, such as vinyl, allyl, propargyl,1-methylvinyl, but-1-enyl, but-2-enyl, but-2-ynyl, 1 methylbut-2-enyl,pent-1-enyl, pent-3-enyl, 3-methylbut-1-ynyl, 1,1-dimethylallyl,hex-2-enyl and 1-methyl-1-ethylallyl;

The term “cycloalkyl” is used herein to mean cyclic radicals, includingbut not limited to, cyclopropyl, cyclopentyl, cyclohexyl, and the like.

The term “cycloalkylalkyl” as used herein refers to a cycloalkyl groupappended to a lower alkyl radical, including, but not limited tocyclohexylmethyl.

The “alkoxyalkyl” mentioned for R substitutes is preferably a groupcontaining a total of 1–22 carbon atoms. As example, methoxyethyl,methoxypropyl, methoxybutyl, ethoxyethyl, ethoxypropyl, ethoxybutyl,n-propoxyethyl, and iso-propoxyethyl, can be mentioned.

The term “alkoxy” as used herein refers to an alkyl group attached tothe parent molecular group through an oxygen atom.

The term “alkoxyalkoxy” as used herein refers to an alkoxy groupattached to the parent molecular group through an alkoxy group.

The term “halo” or “halogen” as used herein refers to I, Br, Cl or F.

The term “carboxy” as used herein refers to the radical —COOH. The term“ester” refers to —COOR; and the term “amide” refers to —CONH₂ or —CONHRor —CONR₂. The term “cyano” as used herein refers to the radical —CN.

Phosphorus containing and other salts of S-alkylisothiouroniumsynthesized in a variety of ways, which are well known in the art, forexample by alkylating thiourea with appropriate trialkylphosphates ordialkylphosphites while heating in an organic solvent.

Without excluding other options, which are listed below, presentlyS-ethylisothiouronium diethylphosphate is the preferred compound for thetreatment of headache, in particular migraine, and nausea or vomiting.Other examples of S-alkylisothiouronium derivatives which can be used totreat migraine according to the present invention include, but are notlimited to, S-methylisothiouronium methylphosphite;S-methylisothiouronium dimethylphosphate; S-ethylisothiouroniummetaphosphate; S-ethylisothiouronium ethylphosphite;S-ethylisothiouronium diethylphosphate; S-propylisothiouroniumpropylphosphite; S-isopropylisothiouronium metaphosphate;S-isopropylisothiouronium isopropylphosphite; S-butylisothiouroniumdibutylphosphate; and S-isobutylisothiouronium isobutylphosphite.

These compounds are known to be safe for human use as it is well knownin the art that phosphorus containing derivatives ofS-alkylisothiouronium have a low toxicity and their LD₅₀ (lethal dose50%) is in the range of 100–1000 mg/kg, which is far above thetherapeutic doses of these compounds.

The anti-headache, anti-migraine, anti-nausea or anti-emetic medicamentof the present invention is preferably packed and is preferablyidentified as having such activity. Such identification can be printed,for example, on a package insert with the medicament or on a package orcontainer which contains the medicament.

A compound according to the present invention can be administered to atreated subject per se, or in a pharmaceutical composition where it ismixed with suitable carriers or excipients.

As used herein a “pharmaceutical composition” refers to a preparation ofone or more of the compounds described herein, or physiologicallyacceptable salts or prodrugs thereof, with other chemical componentssuch as physiologically suitable carriers and excipients. The purpose ofa pharmaceutical composition is to facilitate administration of acompound to an organism.

The term “prodrug” refers to an agent, which is converted into an activeparent drug in vivo. Prodrugs are often useful because in some instancesthey may be easier to administer than the parent drug. They may, forinstance, be bioavailable by oral administration whereas the parent drugis not. The prodrug may also have improved solubility compared to theparent drug in pharmaceutical compositions.

Herein the term “excipient” refers to an inert substance added to apharmaceutical composition to further facilitate administration of acompound. Examples, without limitation, of excipients include calciumcarbonate, calcium phosphate, various sugars and types of starch,cellulose derivatives, gelatin, vegetable oils and polyethylene glycols.

Pharmaceutical compositions may also include one or more additionalactive ingredients, such as, but not limited to, conventionalanti-migraine agents.

Pharmaceutical compositions of the present invention may be manufacturedby processes well known in the art, e.g., by means of conventionalmixing, dissolving, granulating, grinding, pulverizing, dragee-making,levigating, emulsifying, encapsulating, entrapping or lyophilizingprocesses.

Pharmaceutical compositions for use in accordance with the presentinvention thus may be formulated in conventional manner using one ormore physiologically acceptable carriers comprising excipients andauxiliaries, which facilitate processing of the active compounds intopreparations which, can be used pharmaceutically. Proper formulation isdependent upon the route of administration chosen.

For injection, the compounds of the invention may be formulated inaqueous solutions, preferably in physiologically compatible buffers suchas Hank's solution, Ringer's solution, or physiological saline buffer.For transmucosal administration, penetrants appropriate to the barrierto be permeated are used in the formulation. Such penetrants for exampleDMSO, or polyethylene glycol are generally known in the art.

For oral administration, the compounds can be formulated readily bycombining the active compounds with pharmaceutically acceptable carrierswell known in the art. Such carriers enable the compounds of theinvention to be formulated as tablets, pills, dragees, capsules,liquids, gels, syrups, slurries, suspensions, and the like, for oralingestion by a patient. Pharmacological preparations for oral use can bemade using a solid excipient, optionally grinding the resulting mixture,and processing the mixture of granules, after adding suitableauxiliaries if desired, to obtain tablets or dragee cores. Suitableexcipients are, in particular, fillers such as sugars, includinglactose, sucrose, mannitol, or sorbitol; cellulose preparations such as,for example, maize starch, wheat starch, rice starch, potato starch,gelatin, gum tragacanth, methyl cellulose,hydroxypropylmethyl-cellulose, sodium carbomethylcellulose; and/orphysiologically acceptable polymers such as polyvinylpyrrolidone (PVP).If desired, disintegrating agents may be added, such as cross-linkedpolyvinyl pyrrolidone, agar, or alginic acid or a salt thereof such assodium alginate.

Dragee cores are provided with suitable coatings. For this purpose,concentrated sugar solutions may be used which may optionally containgum arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethyleneglycol, titanium dioxide, lacquer solutions and suitable organicsolvents or solvent mixtures. Dyestuffs or pigments may be added to thetablets or dragee coatings for identification or to characterizedifferent combinations of active compound doses.

Pharmaceutical compositions, which can be used orally, include push-fitcapsules made of gelatin as well as soft sealed capsules made of gelatinand a plasticizer, such as glycerol or sorbitol. The push-fit capsulesmay contain the active ingredients in admixture with filler such aslactose, binders such as starches, lubricants such as talc or magnesiumstearate and, optionally, stabilizers. In soft capsules, the activecompounds may be dissolved or suspended in suitable liquids, such asfatty oils, liquid paraffin, or liquid polyethylene glycols. Inaddition, stabilizers may be added. All formulations for oraladministration should be in dosages suitable for the chosen route ofadministration.

For buccal administration, the compositions may take the form of tabletsor lozenges formulated in conventional manner.

For administration by inhalation, the compounds for use according to thepresent invention are conveniently delivered in the form of an aerosolspray presentation from a pressurized pack or a nebulizer with the useof a suitable propellant, e.g., dichlorodifluoromethane,trichlorofluoromethane, dichlorotetrafluoroethane or carbon dioxide. Inthe case of a pressurized aerosol, the dosage unit may be determined byproviding a valve to deliver a metered amount. Capsules and cartridgesof, e.g., gelatin for use in an inhaler or insufflator may be formulatedcontaining a powder mix of the compound and a suitable powder base suchas lactose or starch.

Pharmaceutical compositions for parenteral administration includeaqueous solutions of the active preparation in water-soluble form.Additionally, suspensions of the active compounds may be prepared asappropriate oily injection suspensions. Suitable lipophilic solvents orvehicles include fatty oils such as sesame oil, or synthetic fatty acidsesters such as ethyl oleate, triglycerides or liposomes. Aqueousinjection suspensions may contain substances, which increase theviscosity of the suspension, such as sodium carboxymethyl cellulose,sorbitol or dextran. Optionally, the suspension may also containsuitable stabilizers or agents, which increase the solubility of thecompounds, to allow for the preparation of highly concentratedsolutions.

Alternatively, the active ingredient may be in powder form forconstitution with a suitable vehicle, e.g., sterile, pyrogen-free water,before use.

The compounds of the present invention may also be formulated in rectalcompositions such as suppositories or retention enemas, using, e.g.,conventional suppository bases such as cocoa butter or other glycerides.

The pharmaceutical compositions herein described may also comprisesuitable solid of gel phase carriers or excipients. Examples of suchcarriers or excipients include, but are not limited to, calciumcarbonate, calcium phosphate, various sugars, starches, cellulosederivatives, gelatin and polymers such as polyethylene glycols.

Pharmaceutical compositions suitable for use in context of the presentinvention include compositions wherein the active ingredients arecontained in an amount effective to achieve the intended purpose. Morespecifically, a therapeutically effective amount means an amount of acompound effective to prevent, alleviate or ameliorate symptoms of adisease of the subject being treated.

Determination of a therapeutically effective amount is well within thecapability of those skilled in the art, especially in light of thedetailed disclosure provided herein.

Toxicity and therapeutic efficacy of the compounds described herein canbe determined by standard pharmaceutical procedures in cell cultures orexperimental animals, e.g., by determining the IC₅₀ (the concentrationwhich provides 50% inhibition) and the LD₅₀ (lethal dose causing deathin 50% of the tested animals) for a subject compound. The data obtainedfrom these cell culture assays and animal studies can be used informulating a range of dosage for use in human. The dosage may varydepending upon the dosage form employed and the route of administrationutilized. The exact formulation, route of administration and dosage canbe chosen by the individual physician in view of the patient'scondition. (See e.g., Fingl, et al., 1975, in “The Pharmacological Basisof Therapeutics”, Ch. 1 p.1).

Depending on the severity and responsiveness of the condition to betreated, dosing can also be a single administration of a slow releasecomposition, with course of treatment lasting from several days toseveral weeks or until cure is effected or diminution of the diseasestate is achieved.

The amount of a composition to be administered will, of course, bedependent on the subject being treated, the severity of the affliction,the manner of administration, the judgment of the prescribing physician,etc.

Sustained release tablets or capsules which containS-alkylisothiouronium may be used either before the attack, e.g., inpersons about to undergo chemotherapy or other treatments that are knownto engender nausea or vomiting, in women who are aware that theirpremenstrual period is typically followed by nausea or a migraine, or inthose migraine patients who experience “aura” and can identify this as apre-migraine stage. Also, the tablet or the capsule can be formulated ina way that a portions of the active ingredient is released immediately,to provide an initial migraine alleviation, whereas the other portion isreleased slowly and in measured quantities.

As used herein, the term, “initial migraine alleviation” refers to thereduction or abolition of migraine symptoms within a predetermined timerange, post administration and particularly in the present invention,within about 10–60 minutes post administration.

Each of the tablets or capsules of the present invention preferablycontains between 10 and 300 mg, preferably 20 and 200 mg, morepreferably between 30 and 80 mg of the active compound(S-alkylisothiouronium derivatives). As used herein the term “about”refers to ±20%.

According to another aspect of the present invention there is provided amethod of preparing an anti-headache, anti-migraine, anti-nausea oranti-emesis medicament. The method according to this aspect of thepresent invention is effected by mixing, as an active ingredient, acompound having the general formula (I):

wherein

-   -   R₁ is a linear or branched saturated or unsaturated alkylene,        comprising one to eight carbon atoms optionally substituted with        one or more substituent selected from the group consisting of        halogen, primary or secondary amine, primary or secondary        alcohol, or interrupted by one or more heteroatom selected from        the group consisting of O, N, and S;    -   R₂, R₃, R₄ and R₅ are each independently a hydrogen, hydroxy,        linear or branched lower alkyl, linear or branched lower        alkenyl, linear or branched lower alkynyl, lower alkoxy,        alkoxyalkyl, cycloalkyl, cycloalkylalkyl, lower thioalkoxy,        nitro, amino, cyano, sulfonyl, haloalkyl, carboaryloxy,        carboalkylaryloxy, alkyl sulfoxide, aryl sulfoxide, alkyl        sulfone, aryl sulfone, alkyl sulfate, aryl sulfate, sulfonamide,        thioalkyl, optionally substituted by halogen;    -   A⁻ is a physiologically acceptable anion;    -   together with and a pharmaceutically acceptable carrier or        diluent.

According to a preferred embodiment of the present invention, the methodfurther includes the step of packaging the medicament and identifyingthe medicament as having anti-headache, anti-migraine, anti-nausea oranti-emetic activity as is further described above. The identificationof the medicament as an anti-headache, in particular an anti-migraineagent or as an anti-emetic agent are novel indications forS-alkylisothiouronium derivatives, which are known as hypertensiveagents and were not indicated before for the purposes of treating oralleviating the symptoms of headache, migraine or nausea.

In still another aspect of the present invention there is provided amethod of treating headache, migraine, or nausea The method according tothis aspect of the present invention is effected by administering to asubject a therapeutically effective amount of a compound having thegeneral formula (I):

wherein

-   -   R₁ is a linear or branched saturated or unsaturated alkylene,        comprising one to eight carbon atoms optionally substituted with        one or more substituent selected from the group consisting of        halogen, primary or secondary amine, primary or secondary        alcohol, or interrupted by one or more heteroatom selected from        the group consisting of O, N, and S;    -   R₂, R₃, R₄ and R₅ are each independently a hydrogen, hydroxy,        linear or branched lower alkyl, linear or branched lower        alkenyl, linear or branched lower alkynyl, lower alkoxy,        alkoxyalkyl, cycloalkyl, cycloalkylalkyl, lower thioalkoxy,        nitro, amino, cyano, sulfonyl, haloalkyl, carboaryloxy,        carboalkylaryloxy, alkyl sulfoxide, aryl sulfoxide, alkyl        sulfone, aryl sulfone, alkyl sulfate, aryl sulfate, sulfonamide,        thioalkyl, optionally substituted by halogen;    -   A⁻ is a physiologically acceptable anion;    -   together with and a pharmaceutically acceptable carrier or        diluent.

It should be noted in this respect that in a ongoing clinical trials,which is described in detail in the Examples section that follows, humansubjects were assessed for their response and for the beneficial effectS-ethylisothiouronium diethylphosphate. Unexpectedly, these subjectsshowed a dramatic, beneficial effect of the drug, which was administeredduring the migraine attack. The administered dose was substantiallylower than the effective oral dose which is used for treatinghypotension (which is generally about 100 mg). Moreover, the drug wasfound to be potent in reducing the migraine symptoms within a relativelyshort period of time, around 45 minutes on average, while the subjectwas at the peak of the migraine attack.

Apart from eliminating the acute headache, the drug also eliminated theunpleasant sensation of nausea, photophobia, and improved the impairedsight focusing. The drug was shown to have a fast and prolonged effect.In addition, the rapid mode of action suggests of fast absorption of thedrug. In addition, no side effects were apparent.

These results are extremely unexpected. It will be appreciated in thisrespect that recognized migraine drugs act most quickly whenadministered by the parenteral route. Also, no matter how administered,therapeutic relief of migraine is often not obtained using theserecognized migraine drugs. When administered orally, the recognizedmigraine drugs act significantly more slowly than when parenterallyadministered, such that pain relief, when achieved, may not be apparentfor up to 2–3 hours post-administration.

As used herein the term “therapeutically effective amount” or“therapeutically efficient” as to a drug dosage, refer to dosage thatprovides the specific pharmacological response for which the drug isadministered in a significant number of subjects in need of suchtreatment. The “therapeutically effective amount” may vary according,for example, the physical condition of the patient, the age of thepatient and the severity of the disease. It is emphasized that migraineheadache is not well understood and the etiology of particular migrainesvary, as does the response to particular drugs. Thus, reference to“specific pharmacological response for which the drug is administered ina significant number of subjects in need of such treatment” is arecognition that a “therapeutically effective amount”, administered to aparticular subject in a particular instance will not always abortmigraine onset or relieve an actual migraine headache, even though suchdosage is deemed a “therapeutically effective amount” by those skilledin the art.

The term “prolonged effect” in relation to S-ethylisothiouroniumdiethylphosphate relates to its pharmacokinetic half-life. It should benoted in this respect that in the case reports described in the Examplessection that follows, the migraine attack was eliminated within minutespost administration of the drug, and in the reported cases no additionaltreatment was required.

The preliminary clinical trial revealed another two important issuesthat relate to the “relapse” of the headache and to the side effects ofthe currently marketed anti-migraine drugs, some hours after theadministration. Headache recurrence after successful initial treatmentis another weakness of some currently available anti-migrainepreparations. That is, after a dosage of a known therapeutic agent hasbeen administered to a subject in an effective amount to initially treata migraine attack, and migraine alleviation has been observed, migrainesymptoms occur again from as soon as about 1–8 hours after first reliefto about 12 to 24 hours later. The headache, which occurs under thecircumstances described above has been variously and interchangeablytermed a “rebound,” “relapse,” “recurrent,” “follow on,” or “secondary”headache. The terms not withstanding, it is presently unknown as towhether this later headache is a continuation of the physiological chainof events that caused original headache, or a new headache due to otheror repeated, but unrelated, underlying pathology. It is also possiblethat the follow on headache is a response to therapeutic agents, whichinitially were successful in treating the initial migraine symptoms. Theterms “rebound,” “relapse,” “recurrent” “follow on,” and “secondary” (asdefined below) are considered synonymous as used herein withoutinferring a mechanism or cause of migraine headache.

According to the described case reports, this phenomenon was notobserved while receiving S-ethylisothiouronium diethylphosphate.

It should be noted in this respect that migraine attacks are associatedwith dilation of blood vessels in the head, and relief of a migraineheadache is associated inter alia with the reduction of suchvasodilatation. As a side effect, anti migraine agents can causeabnormal blood flow (by either vasodilatation or vasoconstriction).Thus, the striking therapeutic effect of S-ethylisothiouroniumdiethylphosphate as an anti-migraine agent together with its knownpotency in controlling abnormal blood vessel flow is the answer for thedebilitating effects of migraine symptoms without the side effects ofknown anti migraine agents.

In addition, S-ethylisothiouronium diethylphosphate, can be beneficiallycombined with another anti-migraine agent such as an ergotaminederivative, or a serotonergic agonist. The combined treatment willrequire a lower amount of each drug while the addition ofS-ethylisothiouronium diethylphosphate to a known therapeutic agentswill reduce side effects of the known drugs and will provide initialrelief to the sufferers within minutes.

As was discussed before the compound is formulated for oral, injectable,inhalable or transdermal administration.

Oral administration is by tablets or capsules, wherein the preferreddose is ranging between 10 and 200 mg of the compound, preferably,between 20 and 70 mg of the compound and according the clinical resultsis about 50 mg of the compound. Thus, the therapeutically effectiveamount of the compound ranges between 0.1 and 3.0 mg/kg body weight,preferably between 0.4 and 1.6 mg/kg body weight, more preferably from0.5 and 1.2 mg/kg body weight.

The above ranges of therapeutic effective doses are selected so as toexert a substantial relief in migraine symptoms within 15–60 minutespost administration.

In a preferred embodiment of the present invention the administration ofan S-alkylisothiouronium derivative is effected at or following theonset of a migraine.

Additional objects, advantages, and novel features of the presentinvention will become apparent to one ordinarily skilled in the art uponexamination of the following examples, which are not intended to belimiting. Additionally, each of the various embodiments and aspects ofthe present invention as delineated hereinabove and as claimed in theclaims section below finds experimental support in the followingexamples.

EXAMPLES

Reference is now made to the following examples, which together with theabove descriptions illustrate the invention in a non-limiting fashion.

Example 1 Results of the Clinical Trials in Treatment of Migraine Attackby Difetur Oral Formulation (Tablets)

Study Protocol

Dose escalating exploratory study on the safety and efficacy of Difeturtablets for the treatment of acute migraine attack.

1. Study Objective

The purpose of following exploratory protocol is to evaluate the safetyand potential efficacy of Difetur (S-ethylisothiouroniumdiethylphosphate) tablets, in escalating doses starting at 10 mg and upto 50 mg, in the treatment of a single acute migraine attack. The studywas designed as an open study in a selected population of subjectsclassified according to IHS criteria as suffering from migraineheadaches of moderate or severe intensity, without aura. The study wasconducted according to established international criteria for evaluatingsafety and efficacy for migraine treatment.

2. Study Design

The study was performed as a 5 arm (groups) study. Only female patientsclassified as suffering from migraine without aura, according to IHScriteria are enrolled in the study. Each group consists of ten migrainepatients who are treated during an acute migraine attack with Difeturtablets in a hospital setting. The initial dose of Difetur is 10 mg (1tablet), consequently increasing to 20 mg, 30 mg, 40 mg, and 50 mg. Thetotal number of patients to be enrolled is 50. The patients arehospitalized and followed for at least 4 hours to assess the safety,efficacy and possible side effects of Difetur.

3. Drug Administration

In the first group of 10 patients each receive the initial dose of 10 mgof the study medication in a single tablet form. The dose of 50 mg isgiven as two tablets of 25 mg each. The tablets are individually packedin blister package, and have a label identifying the study medication asan investigational drug. Each dose in an escalating manner is given to10 patients. The medication is swallowed with a glass of water under thesupervision of an attending physician.

4. Efficacy Evaluation

4.1 Primary Efficacy Objective is Headache Reduction.

Headache severity is graded verbally in a 4-points scale: severe (grade4), moderate (grade 3), mild (grade 2), or no pain (grade 1). Success isconsidered as a reduction of the headache severity from a severe ormoderate headache (grade 3–4) to mild or no pain (grade 1–2).

4.2 Secondary Efficacy Targets are the Reduction of Nausea, Vomiting andLight and Sound Sensitivity.

These are assigned for their presence, absence or disappearance asdocumented by the patient.

Study Results.

TABLE 1 Summary of Results in Migraine Headache Treatment (TreatmentInitiated During Migraine Attack). Percentage of Patients Time elapsedto No. Dosage¹ (mg) Benefited by Treatment² Effect³ (min) 1 10 0 — 2 2070 43 3 30 70 58 ¹Dosage of Difetur per treatment. ²Relief of headacheis considered effective if the patient reported a reduction of theheadache severity from severe or moderate (grades 3–4) to mild or nopain (grades 1–2). [Headache severity scale: 1 = No pain; 2 = mild; 3 =moderate; 4 = severe pain]. ³Time after ingestion of drug at which apatient reported headache reduction to grade 1–2.

Unexpectedly, it is now disclosed that the low doses of Difetur, whichare ineffective or less effective at alleviating the severity of themigraine headache, are already effective at reducing or abolishing thesymptoms of nausea Moreover it was observed that the time elapsed untilrelief from nausea was reported was shorter than that recorded forreduction of the severity of the headache. This supports the use of thedrug as an anti-emetic.

TABLE 2 Summary of Results in Emesis Treatment During Migraine Attack.Percentage of Patients Time elapsed until No. Dosage⁴ (mg) Affected byTreatment⁵ Effect⁶ (min) 1 10 70 28 2 20 100 25 3 30 100 29 ⁴Dosage ofDifetur per treatment. ⁵The percent of patients that exhibited apositive anti-emetic response to Difetur administration. ⁶Time afteringestion of drug at which a patient reported termination of emesis.

Example 2 Multiple Doses of Difetur for Relief of Migraine Headache CaseReport 1

Previous medical history: The subject is a smoking, 30 years old femalefirst diagnosed as a classical migraine sufferer at 17 years of age.Except for this she is completely healthy. Until two years ago thefrequency of the migraine attacks was seven episodes per month. Duringthe last two years she was treated with different kinds of recognizedmedications, with little or no success. Due to lack of response to themedical treatment during the migraine attacks, she tried alternativemedicine treatments.

As a result of the S-ethylisothiouronium diethylphosphate treatment thefrequency of migraine attacks she suffered from, was reduced to aboutthree each month. In addition, the nature of the migraine attacks haschanged to become of a weaker strength. The reported effect of theS-ethylisothiouronium diethylphosphate treatment on the migraine painwas that it became significantly weaker. At present, she experiencesapproximately only two migraine attacks monthly, mostly before themenstruation period, during very hot weather conditions, or when extremechanges in the weather occurs. The pre menstruation-period migraineattacks are usually longer and more acute than the other migraineattacks. The duration of each migraine attack lasts 24–72 hours.

Past medical treatment: The medication that she was treated with, priorto the alternative medicine treatments were: Temigran, Migraleve,Imitrex and Zomig. These treatments were terminated due to variousstrong side effects, included hand tremor, shivering, dryness of themouth, nausea and vomiting.

Treatment with S-ethylisothiouronium diethylphosphate:

First attack: The subject suffered an acute migraine attack that lasted72 hours. Despite her intake of prescription medication every two hoursthe intensity of the Migraine associates pain did not change. On thenext day the subject received a single dose of 50 mgS-ethylisothiouronium diethylphosphate (2 tablets of 25 mg each). Thedrug was taken on empty stomach; the subject did not eat nor drinkanything before swallowing the drug. Between 10 to 15 minutes followingadministration the pain abruptly disappeared, as did all other symptoms,which appeared during the migraine attack.

Second attack (three weeks later) The second migraine attack startedduring the night. On the next day the subject received once again 2tablets of S-ethylisothiouronium diethylphosphate (50 mg). This time theintake of the tablets was during the peak of the migraine attack, afterhaving a meal. Within 20 minutes the headache was relieved, the subjectwas able to focus her eyesight, and the photophobia disappeared. Therewas a weak headache but its intensity was reduced. Three hours later thesubject took two more tablets of S-ethylisothiouronium diethylphosphate(50 mg). Within 15 minutes the migraine pain disappeared.

Third attack (two and a half weeks after the second attack) the migraineattack started on her way to work. An hour after onset within the peakof the migraine attack, the subject received 2 tablets ofS-ethylisothiouronium diethylphosphate (each of 25 mg). Drug was takenon empty stomach. Within 11 minutes the migraine symptoms disappeared.

Side effects: No side effects following the intake ofS-ethylisothiouronium diethylphosphate were apparent.

Example 2 Case Report 2

Previous Medical History: The subject is a non-smoking 34 years oldfemale suffering from migraine attacks during the last two years. Thefrequency of the migraine attacks is once a month before themenstruation period. The pain appears in the temples, the sinuses andspreads down to the lower jaw. The duration of the photophobia was about48 hours. So far the subject has not applied to receive specific medicaltreatment and used to take conventional analgesic drugs.

Past medical Treatment: Conventional pain relief (analgesic) drugs.

Treatment with S-ethylisothiouronium diethylphosphate:

First attack: The onset of an acute migraine attack was in the morningand the symptoms grew stronger during the day. Just before noon time thesubject received one tablet of S-ethylisothiouronium diethylphosphate(25 mg). No substantial change in the migraine pain was observed. Twohours later the subject received 2 more tablets of S-ethylisothiouroniumdiethylphosphate (each of 25 mg). Ten minutes later, the migraine paindisappeared.

Second attack (about four weeks after the first attack) The migraineattack started as a consequence of very hot weather conditions. Theintensity of this attack was greater than the usual migraine attacks. Inthe morning, the subject received 2 tablets of S-ethylisothiouroniumdiethylphosphate (50 mg) that were taken on an empty stomach. Within 20minutes of S-ethylisothiouronium diethylphosphate intake there was asignificant relief in migraine pain. Fifteen minutes later the paindisappeared. Later that day, during the afternoon, the subject suffereda weak pain. This time the subject self administered analgesic drugs andthe pain disappeared.

Side effects: No side effects following the intake of 25 or 50 mgS-ethylisothiouronium diethylphosphate were detected by the monitor.

Discussion of the Results

Both case reports and especially the first case show a dramatic,unexpected, beneficial effect of S-ethylisothiouronium diethylphosphateadministered during the migraine attack. The effective dose was abouthalf the effective dose used to treat hypotension (which is about 50–100mg). Moreover, the drug was found to be highly potent in eliminating themigraine symptoms within less than 20 minutes, while the subject was atthe peak of the migraine attack. Apart from eliminating the acuteheadache, the drug also eliminated nausea and the unpleasant sensationof photophobia, and improved the impaired sight focusing. The strikingeffects of the drug were repeated three times in the first subject andtwice in the second subject. It seems that the drug is more effectivewhen administered on an empty stomach. In addition, no side effects weredetected.

Thus, it can be concluded that S-ethylisothiouronium diethylphosphate isa highly potent drug for treating and alleviating migraine symptoms. Ithas a rapid mode of action, an effective low dose, and according to thedescribed case reports it is devoid of side effects.

Example 3 Anti-Emesis in Test Animals

The effect of the test compounds on emesis is tested in ferretsaccording to the general method described by Florezyk, Schurig andBradnet (Cancer Treatment Report, 1982 66(1) 187–9) and summarizedbelow. Both the test compound and cisplatin are prepared andadministered in normal saline.

a) Control—Without Test Compound

Emesis is induced in groups of 6 male ferrets weighing between 1.5–2 kg,by intravenous administration of cisplatin at a dose of 10 mg/kg. Theonset of emesis occurs between 30 and 75 minutes after injection andover a period of 2 hours the number of vomits/retches (episodes) is inthe range 30–60 (average 40 vomits/retches per 2 h). Behavioral changescharacteristic of emesis are also noted.

b) With Test Compound

The test compound is administered to groups of 6 male ferrets (1.5–2 kg)by intravenous administration at doses of 0.01, 0.1 and 1 mg/kg,immediately prior to administration of cisplatin as described above. Theanimals are observed for 3 hours.

The effect of the test compound on emesis is also evaluated followingintraperitoneal administration, using a similar procedure to thatdescribed above. Thus cisplatin is administered intraperitoneally to agroup of male ferrets at a dose of 5–10 mg/kg, and the time to onset ofemesis and the number of emetic episodes are recorded. In a second groupof male ferrets the test compound is administered at a dose of 1 mg/kgi.p. 30 minutes before and 1 hour after intraperitoneal administrationof cisplatin.

Example 4 Clinical Trials in Treatment of Migraine Attack by IntravenousDifetur

1. Study Summary

The purpose of following exploratory protocol was to evaluate the safetyand potential efficacy of Difetur 10% solution for injection, in dose0.6 mg/kg, in treatment of a single acute migraine attack. The study wasdesigned as an open study in a selected population of subjectsclassified according to IHS criteria as suffering from migraineheadaches of moderate or severe intensity, without aura. The study wasconducted according to established international criteria for evaluatingsafety and efficacy for migraine treatment.

2. Drug Administration

Difetur was presented as 10% (100 mg/mL) solution in 1 mL ampoules. Itwas dissolved in 100 mL of saline solution in intravenous device beforetreatment. The dose of Difetur was 0.6 mg/kg, given by intravenous dripduring 10 min.

3. Efficacy Evaluation

Headache severity was graded verbally on a 5-point scale: very severe(grade 4), severe (grade 3), moderate (grade 2), mild (grade 1), no pain(grade 0). Success was considered as reduction of the headache severityfrom very severe, severe or moderate (grade 4–2) to mild or no pain(grade 1–0).

4. Study Results.

13 patients with various grades of headache severity were included inthe study. Except for one patient in whom no headache reduction wasnoted, all the rest had significant headache relief. The efficacy andtime elapsed to effect are presented in table below:

TABLE 3 Summary of Results in Migraine Headache IV Treatment HeadacheNo. of Percentaoe of Patients Mean time elapsed to grade Patients.Benefited by Treatment¹ Effect (min)² 4 1 100% 50 3 4 100% 25.5 2 8 87%13.7 ¹Success was considered as reduction of the headache severity fromvery severe, severe or moderate (grade 4–2) to mild or no pain (grade1–0). ²Time after initiation of treatment after which a patient reportedheadache reduction to severity grade 1–0.

Although the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the spirit and broad scopeof the appended claims. All publications, patents and patentapplications mentioned in this specification are herein incorporated intheir entirety by reference into the specification, to the same extentas if each individual publication, patent or patent application wasspecifically and individually indicated to be incorporated herein byreference. In addition, citation or identification of any reference inthis application shall not be construed as an admission that suchreference is available as prior art to the present invention.

1. A method of treating headache or migraine, the method comprising thestep of administering to a subject in need of such treatment atherapeutically effective amount of a composition consisting essentiallyof (a) a compound selected from the group consisting ofS-methylisothiouronium methylphosphite; S-methylisothiouroniumdimethylphosphate; S-ethylisothiouronium metaphosphate;S-ethylisothiouronium ethylphosphite; S-ethylisothiouroniumdiethylphosohate; S-propylisothiourium propylphosphite;S-isopropylisothiouronium metaphosphate; S-isopropylisothiouroniumisopropylphosphite; S-butylisothiouronium dibutylphosphate; andS-isobutylisothiouronium isobutylphosphite, and (b) a pharmaceuticallyacceptable carrier or diluent; wherein the composition is formulated astablets or capsules.
 2. The method of claim 1, wherein each of saidtablets or capsules comprises between 10 and 300 mg of the compound. 3.The method of claim 1, wherein each of said tablets or capsulescomprises between 20 and 200 mg of the compound.
 4. The method of claim1, wherein each of said tablets or capsules comprises between 30 and 80mg of the compound.
 5. The method of claim 1, wherein saidtherapeutically effective amount ranges of the compound between 0.1 and3 mg/kg body weight.
 6. The method of claim 1, wherein saidtherapeutically effective amount ranges of the compound between 0.4 and1.6 mg/kg body weight.
 7. The method of claim 1, wherein saidtherapeutically effective amount ranges of the compound between 0.5 and1.2 mg/kg body weight.
 8. The method of claim 1, wherein said whereinthe compound is S-ethylisothiouronium diethylphosphate.
 9. The method ofclaim 1, wherein said therapeutically effective amount is selected suchthat less than one hour after administration a substantial relief inmigraine symptoms is experienced.
 10. The method of claim 1, whereinsaid step of administering the compound is effected following an onsetof a headache or a migraine.
 11. The method of claim 1, wherein saidstep of administering the compound is effected at onset of a headache ora migraine.
 12. The method of claim 1, wherein the carrier or diluentcomprises a sugar, a starch or cellulose preparation or aphysiologically acceptable polymer and optionally includes adisintegrating agent or a salt thereof.
 13. A method of alleviatingnausea or vomiting, the method comprising the step of administering to asubject suffering from nausea or vomiting a therapeutically effectiveamount of a composition consisting essentially of (a) a compoundselected from the group consisting of S-methylisothiouroniummethylphosphite; S-methylisothiouronium dimethylphosphate;S-ethylisothiouronium metaphosphate; S-ethylisothiouroniumethylphosphite; S-ethylisothiouronium diethylphosphate;S-propylisothiouronium propylphosphite; S-isopropylisothiouroniummetaphosphate; S-isopropylisothiouronium isopropylphosphite;S-butylisothiouronium dibutylphosphate; and S-isobutylisothiouroniumisobutylphosphite, and (b) a pharmaceutically acceptable carrier ordiluent; wherein the composition is formulated as tablets or capsules.14. The method of claim 13, wherein each of said tablets or capsulescomprises between 10 and 300 mg of the compound.
 15. The method of claim13, wherein each of said tablets or capsules comprises between 20 and200 mg of the compound.
 16. The method of claim 13, wherein each of saidtablets or capsules comprises between 30 and 80 mg of the compound. 17.The method of claim 13, wherein said therapeutically effective amountranges of the compound between 0.1 and 3 mg/kg body weight.
 18. Themethod of claim 13, wherein said therapeutically effective amount rangesof the compound between 0.4 and 1.6 mg/kg body weight.
 19. The method ofclaim 13, wherein said therapeutically effective amount ranges of thecompound between 0.5 and 1.2 mg/kg body weight.
 20. The method of claim13, wherein the compound is S-ethylisothiouronium diethylphosphate. 21.The method of claim 13, wherein the carrier or diluent comprises asugar, a starch or cellulose preparation or a physiologically acceptablepolymer and optionally includes a disintegrating agent or a saltthereof.
 22. A method of alleviating nausea or vomiting resulting fromthe administration of an anticancer agent or treatment, the methodcomprising the step of administering to a subject in need thereof atherapeutically effective amount of a composition that comprises (a) acompound having the general formula:

wherein, R₁ is a linear or branched saturated or unsaturated alkylene,comprising one to eight carbon atoms optionally substituted with one ormore substituent selected from the group consisting of halogen, primiarysecondary or tertiary amine, primary, secondary or tertiary alcohol, orinterrupted by one or more heteroatom selected from the aroup consistingof O, N, and S; R₂ , R₃, R₄, and R₅ are each independently a hydrogen,hydroxy, liner or branched lower alkyl, linear or branched loweralkenyl, liner or branched lower alkynyl, lower alkoxy, alkoxyalkyl,cycloalkyl, cycloalkylalkyl, lower thioalkoxy, nitro, amino, cyano,sulfonyl, haloalkyl, carboaryloxy, carboalkylaryloxy, alkyl sulfoxide,aryl sulfoxide, alkyl sulfone, aryl sulfone, alkyl sulfate, arylsulfate, sulfonamide, thioalkyl, optionally substituted by halogen; A⁻is a physiologically acceptable anion, and (b) a pharmaceuticallyacceptable carrier or diluent; wherein the composition is administeredtogether with or prior to the administration of the anti-cancer agent ortreatment.
 23. The method of claim 22, wherein the anticancer agent ortreatment is selected from the group consisting of chemotherapy orradiotherapy.
 24. The method of claim 22, wherein the carrier or diluentcomprises a sugar, a starch or cellulose preparation or aphysiologically acceptable polymer and optionally includes adisintegrating agent or a salt thereof.